Method of treating polyester filaments



United States Patent 3,335,209 METHOD OF TREATING POLYESTER FILAMENTSHerbert S. Morgan, Jr., Apex, and Horace M. Robinson, In, Cary, N.C.,assignors to Monsanto Company, St. Louis, Mo., a corporation of DelawareN0 Drawing. Filed May 18, 1966, Ser. No. 550,929 5 Claims. (Cl. 264-136)This application is a continuation-in-part of our copendingapplications, Ser. No. 290,296, filed June 25, 1963, entitledImprovement in Polyester Fiber Manufacture and Product Obtained Thereby,and Ser. No. 290,297, filed June 25, 1963, entitled Improvement inPolyester Fiber Manufacture and Product Obtained Thereby, both nowabandoned.

This invention relates to an improved method for producing articlesprepared from high molecular weight synthetic linear polyesters. Moreparticularly, it relates to an improved method for improving the surfacecharacteristics of articles prepared from synthetic linear polyesters.

It is well known to apply finishing agents to textile materials in orderto impart to the textile materials certain desirable properties, such asantistatic protection, stiffness, sizing, softness, lubricity, waterrepellency, shrinkage resistance, flame retardance, and the like. Inaddition, in the manufacture of filament yarns from such syntheticlinear polymers as the polyamides, polyesters, polyalkylenes,polyurethanes, polycarbonates, acrylonitrile poly mers, and the like, ithas been known that ultimate yarn tenacity can be greatly increased byemploying the technique of drawing, which comprises stretching the yarnfilaments after their formation to increase molecular orientation.

Although the drawing operation can be conducted by various means, acommon procedure is to employ tWo filament advancing devices generallyknown as a feed roll and draw roll. Filament stretching is achieved byrunning these rolls at differential speeds with the amount of stretchingor drawing being determined by the ratio of the peripheral speeds of thetwo rolls. In order to localize the point at which stretching occurs, abraking device is sometimes placed between the feed roll and draw roll.Generally, the braking device consists of a pin, called the draw pinaround which the yarn is wrapped a number of times. The draw pinintroduces frictional drag on the moving filaments which causesstretching to take place in the area of the draw pin. The introductionof frictional drag to localize stretching is utilized in those instanceswhere there is a tendency for non-uniform drawing to occur since greateruniformity can be obtained by employing this procedure.

It has been known that the drawing operation can sometimes befacilitated when the yarn temperature is elevated during drawing. Theheating may be carried out by inserting a hot pin, a hot plate, or hotfluid bath between the feed roll and draw rolls of the drawing apparatusor by using a heated feed roll. Elevated temperatures are effectivebecause intermolecular forces are diminished by the resulting increasein molecular activity, and therefore the ratio of the force required todraw the yarn to that required to break it is lessened. Permissibletemperatures which may be used in hot drawing vary somewhat with thenature of the polymer from which the yarn is formed, since the maximumtemperature which can be employed is limited by the polymer stickingpoint. It is a common practice to employ a hot drawing technique whenprocessing yarn for use in products which require great tensilestrength, as for example in the manufacture of reinforcement cards forinflatable tires.

A particularly troublesome problem encountered when drawing at eitherambient or elevated temperatures is the occurrence of filament breakageduring te drawing operation. Thus, at times one .or more individualfilaments in the thread line may break and wrap around the draw roll oras sometimes happens the entire thread line may break, in which caseproduction is stopped until adjustment can be made. Such filamentbreakage not only affects labor requirements and productivity, but theproduct quality is also affected in an adverse manner.

The principal cause of filament breakage while drawing is the build-upof excessive tension of the yarn which in turn is intensified, for themost part, by inter-filament friction and by the generation of excessivefriction as the yarn passes over the draw pin when such device isemployed.

It is known that excessive yarn tensions resulting from the developmentof unduly high and variable frictions during drawing can be reduced byapplying to the yarn various anti-friction conditioning agents before itis drawn. These agents are generally applied from an aqueous vehiclerather than from non-aqueous systems to afford a more uniformdistribution and better control over the amount of active agent which isdeposited on the yarn. These factors are of considerable importance andcannot be controlled when a non-aqueous solvent, for example, isemployed as a vehicle. Non-aqueous solvents are highly objectionablebecause of problems of toxicity and of high solvent retention on theyarn, and also a resulting serious impairment of the drawing operation.

In the case of fibers prepared from high molecular weight syntheticlinear polyesters, it is known that these fibers when freshly spun maybe slowly cold drawn by hand or rapidly hot drawn over heated surfacesby the methods discussed above. However, when undrawn polyester fibersare allowed to age or lag, the polyester fiber is known to change itsamorphous nature and the aged fiber crystallizes causing it to becomevery brittle and difficult to draw uniformly. This condition ismagnified during the drawing step where the individual filaments breakat the draw pin and by filament wraps accumulating on the drawing rollsas discussed previously. In some cases, slow drawing speeds can be usedto help alleviate this condition to some extent, but this seriouslylimits the quantity of yarn or fiber which can be drawn in a givenperiod of time. In commercial production it is necessary to testfilament coming from spinning lines for proper physical and chemicalcharacterizations. In addition, it is often economical to hold upfilament obtained from several spinning positions until filament from anumber of such spinning positions may be combined for use in a singledrawing operation. The breakdown of equipment often causes filament fromthe spinning positions to be held up prior to the drawing operation.Although the tendency for brittleness, excessive yarn tensions, and thelike, to develop during lagged drawing of polyester fibers may bereduced somewhat by pretreatment with certain known conditioning agentsof the prior art, there is a continuing need for treating compositionswhich are capable of greater effectiveness in coping with the problem.

It is an object of this invention to improve the process step of drawinghigh molecular weight synthetic linear polyester filament which havebeen lagged.

It is another object of the present invention to provide staticprotection and lubrication for improved processing of high molecularweight synthetic linear polyester filament.

It is a further object of this invention to provide a method of reducingthe fuming tendency of high molecular weight synthetic linear polyesterfilament finishes during a hot drawing step.

Other objects and advantages of this invention will become readilyapparent from the detailed description thereof immediately following.

It has now been found that brittleness of undrawn high molecular Weightsynthetic linear polyester filaments which have been lagged forconsiderable lengths of time between the extrustion step and the drawingstep and the build up of excessive yarn tensions during the drawing ofsaid filaments can be greatly minimized by treating the filamentsimmediately after extrusion with an aqueous emulsion, the solids contentof which 20 to 100 percent by weight of (1) a member selected from thegroup consisting of a non-ionic surface active ester and a non-ionicsurface active ester condensed with ethylene oxide and (2) from about to80 percent by weight of a non-ionic surface active polyether.

The lag time of the filaments referred to for the purposes of thisinvention is that time between the extrusion of the filaments and thedrawing of the filaments required comprises from about for properphysical and chemical characterizations of the spun polyester filamentsto allow proper quality control segregation necessary for thedisposition of the final product. The minimum lag time in commercialoperation may routinely run from about 12 to 24 hours. However, duringdifficult times of quality assessment, this lag time may run forextended periods up to about 30 days. Characterizations which must bechecked normally as a routine matter are tensile properties, dyeing andcolor characteristics, heat and light stabilities, byproducts andimpurity contamination, and the like. In addition, economics andequipment break-down many times'cause holdups between the filamentextrusion step and the filament drawing step.

The esters comprising an essential part of the agents of this inventionare preferably long chain fatty acid partial esters of polyhydricalcohols or their anhydrides, such as sorbitan monopalmitate andsorbitan monolaurate. These long chain fatty acid partial esters may becondensed with about 4 to moles of ethylene oxide if de-.

sired. The non-ionic surface active agents referred to in general aspolyethers, are prepared by condensing a waterinsoluble hydroxy-fattyacid, or ester of such acid, or mixtures of acid and ester, with from150 to 250 moles of ethylene oxide.,

Among the polyhydric alcohols or anhydrides from which the partialesters may be made are those having from 2 to 8 carbon atoms, such asmanitol, sorbitol, glucose, erythritol, pentaerythritol, glycols such asethylene glycol, triethylene glycol, propylene glycol, diethyleneglycol, tetraethylene glycol, and the like. Various saturated orunsaturated aliphatic acids may be reacted with the polyhydric alcoholsin making the partial esters. A preferred group of partial esters arethose containing a single ester linkage. However, partial esterscontaining more than one ester linkage may be used.

The acids used in making the partial esters may he saturated orunsaturated aliphatic acids containing from 10 to 20 carbon atoms.Preferredacids are those which are saturated or contain one olefinicgroup. Examples of such acids include monoolefinic unsaturated acidssuch as 7- hexadecenoic acid, 10- undecenoic acid, 13-docosenic and9-octadecenoic acid; substituted olefinic acids, for example, suchhydroxy olefinic acids as l6-hydroxy-7-hexadecenoic and12-hydroxy-9-octadeceneoic acid; halogenated unsaturated acids, forexample, monochloro-9-octadecenoic acid, monochloro-12-9-octadecenoicacid, and halogenated acids derived by dehydration of the castor oilacids followed by chlorination; usaturated fatty acids such as decanoicacid, undecanoic acid, dodecanoic acid, trideca-.

noic acid, tetradecanoic acid, pentadecanoic acid, hexadecanoic acid,heptadecanoic acid, octadecanoic acid, and,

nonadecanoic acid. These saturated acids may also have straight orbranched chains, or substituted chain, and may be substituted, forexample, with chlorine mother halogen atoms, for example,monochloro-octadecanoic acid, and the like. Specific partial esterssuitable for use in this invention include glyceryl monohexadeconoic,glyceryl monododecanoate, glyceryl mono-9-hydroxyoctadecanoate, glycerylmono-12l-hydroxyoctadecanoate, sorbitan ene glycol monooctadecanoate,diethylene glycol mono-- octadecanoate, and sorbitan monooctadecanoate.

Examples of hydroxy fatty acids which can be used as such or in the formof partial esters with the polyhydric alcohols set forth above, forcondensation withethylene oxide to form the ether portion of thecompositions of this invention, include both saturated and unsaturatedhydroxy acids such as 12-hydroxy-octadecanoic, l2-hydroxy-dodecanoicacid, 16-hydroxyhexadecanoic acid, 11- hydroxy-hexadecanoic acid,IO-hydroxy-octadecanoic acid, 3,12-dihydroxy-palmitic acid,9,10,l6-hydroxy-hexadecanoic acid, 9,10,12,13-hydroxy-octadecanoic acid,16-hydroxy-7-hexadecanoic acid, and l2-hydroxy-9-octadecanoic acid.

The synthetic linear condensation polyesters contemplated in thepractice of this invention are those formed from dicarboxylic acids andglycols, and copolyesters or modifications of these-polyesters andcopolyesters. In a highly polymerized condition, these polyesters andcopolyesters can be formed into filaments and the like.

The polyesters and copolyesters specifically useful in the instantinvention are those resulting from heating One or more of the glycols ofthe series HO(CH OH, in which n is an integer from 2 to 10, with one ormore dicarboxylic acids, or ester-forming derivatives thereof. Among thedicarboxylic acids and ester-forming derivatives thereof useful in thepresent invention are terephthalic acid,

isophthalic acid,

sebacic acid,

adipic acid, p-carboxyphenoacetic acid, succinic acid,p,p'-dicarboxybiphenol, p,p'-dicarboxycarbanilide,p,p'-dicarboxythiocarbanilide, p,p'-dicarboxydiphenylsulfone,p-carboxyphenoxyacetic acid, p-carboxyphenoxypropionic acid,p-carboxyphenoxybutyric acid, p-carboxyphenoxyvaleric acid,p-carboxyphenoxyhexanoic acid, p-carboxyphenoxyheptanoic acid,p,p-dicarboxydiphenylmethane, p,p-dicarboxydiphenylethane,p,pT-dicarboxydiphenylpropane, p,p'-dicarboxydiphenylbutane,p,p-dicarboxydiphenylpentane, p,p'-dicarboxydiphenylhexane,p,p-dicarboxydiphenylheptane, p,p'-dicarboxydiphenyloctane,p,p-dicarboxydiphenoxyethane, p,p-dicarboxydiphenoxypropane,p,p'-dicarboxydiphenoxybutane, p,p'-dicarboxydiphenoxypentane,p,p-dicarboxydiphenoxyhexane, 3-alkyl 4-(beta-carboxy ethoxy) benzoicacid, oxalic acid,

glutaric acid,

pimelic acid,

suberic acid,

azelaic acid and the dioxy acids of ethylenedioxide. having the generalformula,

HOOC(CH -OCH CH O-(CH ,COOH wherein n is an integer from 1 to 4, and thealiphatic and cyeloaliphatic aryl esters and half esters, ammoniumavailability of terephthalic acid and ethylene glycol, from which it ismade. It also has a relatively high melting point of about 250 through255 C. and this property is particularly desirable in the manufacture offilaments in the textile industry.

Among the modified polyesters and copolyesters which are useful in thepractice of the present invention are those polyesters mentioned abovemodified with dialkyl esters of saturated essentially linear aliphaticdicarboxylic acids containing 20 carbon atoms having the general formularank! (H) R1C-(UJ- A---------CO-R3 wherein R and R are alkyl radicalscontaining from 1 to 10 carbon atoms and more preferably are alkylhydrocarbon radicals containing from 1 to carbon atoms including methyl,ethyl, propyl, isopropyl, n-butyl, sec. butyl, isobutyl, n-amyl,isoamyl, and the like; A is a linear saturated aliphatic radicalcontaining from 14 to 18 carbon atoms in its chain; n is an integer ofeither 1 or 2; and y is an integer from 0 to 2. The total number ofcarbon atoms in A and the side chains thereof is 18. R and R may be thesame or may be different alkyl radicals. Representative dialkyl estersfound useful in this invention include dialkyl 1,20-eicosane dioate,dialkyl S-ethyl octadecene-l, l8-dioate, dialkyl dimethyl octadecane-l,18-dioate, dialkyl diethylhexadecane-l, 16-dioate and the like, wherethe dialkyl groups are methyl, ethyl, propyl, and the like includingalkyl hydrocarbon radicals containing from 1 to 5 carbon atoms. Mixturesof any of the materials described above may also be used. For example,mixtures of above 20 to 80 weight percent of dimethyl l,20-eicosanedioate and about 80 to 20 weight percent of dimethyl 8-ethyloctadecane-1,18-dioate are quite useful. The amounts of necessaryreactants employed to make the modified polyesters, on a molar basis,are ordinarily one mole equivalent of a mixture of the two types ofdialkyl esters of aromatic and C dicarboxylic acids and a molar excessof the glycol. In the mixture of the dialkyl esters, the dialkylaromatic dicarboxylic acid esters are presented in amounts from about 65to 95 weight percent and the dialkyl esters of the aliphatic Cdicarboxylic acid is present in amounts from about 35 to about 5 weightpercent.

Among the modified polyesters and copolyesters which are useful in thepractice of the present invention are the polyesters and copolyestersmentioned above modified with chain-terminating groups havinghydrophilic properties, such as the monofunctional ester-formingpolyesters bearing the general formula wherein R is an alkyl groupcontaining 1 to 18 carbon atoms or an aryl group containing 6 to carbonatoms, and m and n are integers from 2 to 22, and x is a whole numberindicative of the degree of polymerization, that is, x is an integerfrom 1 to 100 or greater. Examples of such compounds aremethoxypolyethylene glycol, ethoxypolyethylene glycol,n-propoxypolyethylene glycol, isopropoxypolyethylene glycol,butoxypolyethylene glycol, phenoxypolyethylene glycol,methoxypolypropylene glycol, methoxypolybutylene glycol,phenoxypolypropylene glycol, phenoxypolybutylene glycol,methoxypolymethylene glycol, and the like. Suitable polyalkylvinylethers having one terminal hydroxy group are the addition polymersprepared by the homopolymerization of alkyl vinyl ethers wherein thealkyl group contains from 1 to 4 carbon atoms. Examples of suchchain-terminating agents are hydroxy polymethylvinyl ether, hydroxypolyethylvinyl ether, hydroxy polypropylvinyl ether, hydnoxypolybutylvinyl ether, hydroxy polyisobutylvinyl ether, and the like. Thechain-terminating agents or compounds may be employed in the preparationof the modified polyesters, in amounts ranging from 0.05 mole percent to4.0 mole percent, based on the amount of dicarboxylic acid or dialkylester thereof employed in the reaction mixture. It is to be noted thatwhen chain-terminating agents are employed alone, i.e., without achainbranching agent, the maximum amount that can be employed in thereaction mixture is 1.0 mole percent. Thus, unexpectedly, the additionof controlled amounts of chain-branching agents along with thechain-terminating agents allows the introduction of an increased amountof the latter into the polymer chain that is otherwise possible whenemploying the chain-terminating agents alone.

One will readily appreciate that the weight percent of chain-terminatingagent which may be employed in this invention will vary with themolecular Weight of the agent. The range of average molecular weight ofthe chain-terminating agents suitable for use in this invention is from500 to 5000, with those agents having a molecular weight in the range of1000 to 3500 being preferred.

Materials suitable as chain-branching agents or crosslinking agents,which are employed to increase the viscosity or molecular weight of thepolyesters, are the polyols which have a. functionality greater thantwo, that is, they contain more than two functional groups, such ashydroxyl. Examples of suitable compounds are pentaerythritol; compoundshaving the formula wherein R is an alkylene group containing from 3 to 6carbon atoms and n is an integer from 3 to 6, for example glycerol,sorbitol, hexane triol-1,2,6, and the like; compounds having the formulawherein R is an alkyl group containing from 2 to 6 carbon atoms, forexample, trimethylol ethane, trimethylol propane, and the like compoundsup to trimethylol hexane; and the compounds having the formula wherein nis an integer from 1 to 6. As examples of compounds having the aboveformula there may be named trimethylol benzene-1,3,5 triethylolbenzene-1,3,5, and the like.

Aromatic polyfunctional acid esters may also be employed in thisinvention as chain-branching agents and particularly those having theformula and in which R, R, and R" are alkyl groups containing 1 to 3carbon atoms and R is hydrogen or alkyl groups having 1 to 2 carbonatoms. As examples of compounds having the above formula there may benamed trimethyl trimesate, tetramethyl pyromellitate, tetramethylmellophonate, trimethyl hemimel litate, trimethyl trimellitate,tetramethyl prehnitate, and the like. In addition, there may be employedmixtures of the above esters which are obtained in practical synthesis.That is, in most instances when preparing any of the compounds havingthe above formula, other related compounds having the same formula maybe present in small amounts as impurities. This does not alfect thecompound as a chain-branching agent in the preparation of the modifiedpolyesters and copolyesters described herein.

The chain-branching agents or cross-linking agents may be employed inthe preparation of the polyesters and copolyesters in amounts rangingfrom 0.05 mole percent to 2.4 mole percent, based on the amount ofdicarboxylic acid or diallcyl ester thereof employed in the reactionmixture. The preferred range of chain-branching agent for use in thepresent invention is from 0.1 to 1.0 mole percent. In the practice ofthe present invention, the calculated amounts of chain-terminating agentor chainterminating agent and chain-branching agent or crosslinkingagent are charged to the reaction vessel at the beginning of the firststage of the esterification reaction and the reaction proceeds as in anywell-known esterification polymerization.

The highly polymeric linear condensation polymers selected from thegroup consisting of polyesters and polyester-amides, which contain inthe molecular structure a substantial proportion of recurring groupshaving the following structural formula CHz-CH2 H-0H2 wherein thesubstituted cyclohexane ring is selected from the group consisting ofthe cis and trans isomers thereof may be used in the practice of thisinvention. These polymeric linear polyesters and polyester-amides may beprepared by a process comprising condensing (1) either of cis or thetrans isomer or a mixture of these isomers of 1,4-cyclohexanedimethanolalone or' mixed with another bifunctional reactant with (2) abifunctional carboxy compound.

The bifunctional reactants which can be employed contain no otherreactive substituents which would interfere with the formation of ahighly polymeric linear polymer when condensed with1,4-cyclohexanedimethanol or a mixture thereof with such bifunctionalreactants. These bifunctional reactants adapted for the preparation oflinear condensation polymers are quite well known and have beendiscussed earlier.

The 1,4-cyclohexanedimethanol employed in any of the processes formaking condensation polymers can be used in combination with anadditional bifunctional coreactant such as when employing a mixture ofglycols (it is advantageous to use amounts of the1,4-cyclohexanedimethanol equal to at least 50 mole percent of the totalof such coreactants employed although smaller proportions can alsobeused). The various bifunctional coreactants which can be employed inadmixture with 1,4- cyclohexanedimethanol include other glycols andcompounds which do not necessarily react with a glycol, e.g., anaminoalcohol. Such coreactants also include diamines, or aminocarboxycompounds.

The bifunctional reactants containing functional groups which can becondensed with 1,4-cyclohexanedimethanol or mixtures thereof arebifunctional compounds capable of condensation so as to form highlypolymeric linear condensation polymers. Such bifunctional compounds canbe solely inter-reactive with a glycol, e.g., a diearboxylic acid orthey can be both (a) coreactive in the sense they can be used'in lieu ofor as a partial replacement of the glycol in a polyester, and (b)interreactive in the sense that they condense with a glycol or abifunctional compound which can be employed in lieu of a glycol. Forexample, 6-amino-caproic acid is both coreactive in that the amino groupis of the type which can be used in lieu of a hydroxy radical of aglycol and also inter-reactive in the sense that the carboxylic groupwill react with the hydroxy of a glycol or the amine of a bifunctionalcompound which can be used in lieu of a glycol. The bifunctionalcompounds which are solely inter-reactive with a glycol include'dicarboxylic acids, carbonates, and the like. The other bifunctionalinterreactive compounds include aminocarboxy compounds, or hydroxycarboxy compounds.

The modified linear condensation polyesters, used in accordance with'the present invention, have specific viscosities in the range of about0.1 to about 1.0, which represent fiberwhere n is defined as the ratioof the viscosity of a solution of 0.5 gram of the polymer in 100 ml. ofm-cresol to the viscosity of the solvent, both at 25", C.

The aqueous emulsions which are used'in the practice of this inventionmay contain up to 20 per-cent solids by weight without exceeding theviscosity limits normally used for conditioning agents used in yarnproduction, with from about 2 to about 15 percent solids being generallypreferred. By the term solids as used herein, there is mean the totalityof ingredients exclusive of the aqueous vehicle without regard tophysical state. The solids may contain from about 20 to 100 percent byweight of the non-ionic surface active ester component defined above andfrom about 0 to percent by weight of the nonionic surface activepolyether defined above. It is preferred that the solids contain fromabout '60 to percent by weight of the non-ionic surface active estercomponent defined above and from about '0 to 40 percent by weight of thenon-ionic surface active polyether component defined above.

Conventional methods may be employed in formulating the. aqueousemulsion. A simple and convenient method is merely to :mix the materialstogether, heat them until the solid materials melt, and then add themolten blend of ingredients to the aqueous vehicle with vigorousmechanical agitation. During this addition step, the water should bemaintained atan elevated temperature which is at or above the meltingpoint of the ingredients.

Generally, good results are obtained in both cold and hot drawingoperations when the conditioning agent is applied in an amount such thatthe solids deposited on the fiber constitute from about 0.1 to about 1.5percent by weight, based on the weight of the fiber. Although lesser orgreater amounts may be used, best results are obtained when the amountof solids deposited on the fiber is within this range.

As has been emphasized, the above-described treating agent is applied tothe filaments or fiber immediately during or after spinning and prior todrawing. A conventional and convenient technique of application is tocontact the fiber while moving or advancing in the course of productionwith a roll which is made to rotate so that its. lower portion dips intoa pan containing the treating composition. The treating agent is pumpedfrom a reservoir to the pan or other container and a constant level ismaintained by an overflow pipe or similar device. Other suitable methodsand devices may be employed suchas the use of a wick or split roll orthe fiber may be passed through a bath containing a treating agent.

The fibers herein described may be modified by incorporation therein ofvarious modifying agents. Illustrative .of suitable modifying agentsthat may be incorporated into the fibers are pigments, plasticizers,resins, diluents, water repellents, waxes, luster modifiying agents,flame repellents, antistatic agents, softeners, and the like.

The following examples specifically illustrate the manner in which theprocess of the present invention is conducted and the advantagesobtained thereby. That is, advantages which accrue both wtih respectto-improvement of the drawing operation as well as in the ultimate yarnproducts. The examples are given by way of illustration only and are notto be construed as limitative.

EXAMPLE 1 Filaments :were formed by the melt extrusion of a polyethyleneterephthalate polymer modified with approxi-.

molecular weight of about 2000 and approximately 0.125 percent, based onthe weight of the polyethylene terephthalate, of pentaerythritol. Nofinish was applied to these filaments. The filaments were then lagged orheld for 17 hours at room temperature, about 23 C. after which time theycould not be uniformly cold or hot drawn. Additional filaments werelagged 8 days at room temperature at which time they could not be colddrawn and when hot drawn they were so brittle at a draw ratio of 5.2that a continuous drawing line could not be maintained over a short timeperiod of minutes.

EXAMPLE 2 Filaments were formed by the melt extrusion of polyethyleneterephthalate modified with approximately 6 percent, based on the weightof the polyethylene terephthalate, of methoxy polyethylene glycol havinga molecuar weight of about 2000, and approximately 0.125 percent, basedon the weight of polyethylene terephthalate of pentaerythritol. Thesefilaments were then treated with an aqueous emulsion containing percentsolids, the solids content of which comprised about 60 percent by weightof sorbitan monopalmitate and about 40 percent by weight of castor oilcondensed with 200 moles of ethylene oxide. The treating agent wasapplied by means of a rotating roll in an amount such that 0.83 percentsolids were deposited on the filaments, based on the weight of thefilaments. The filament yarns were then divided into three parts. Thefirst part was immediately hot drawn on a conventional draw-twistmachine at a draw ratio of 4.4lX with excellent results. The second partwas lagged for 7 days after which it was hot drawn on a conventionaldraw-twist machine at a draw ratio of 4.4lX with excellent results. Thethird part was lagged 31 days after which it was hot drawn on aconventional draw-twist machine at a draw ratio of 4.4lX wtih excellentresults.

EXAMPLE 3 Filaments were formed by the melt extrusion of polyethyleneterephthalate modified with aproximately 6 percent, based on the weightof the polyethylene terephthalate, of methoxy polyethylene glycol havinga molecular weight of about 2000, and approximately 0.125 percent, basedon the weight of polyethylene terephthalate, of pentaerythritol. Thesefilaments were then treated With an aqueous emulsion containing 10percent solids, the solids content of which comprised sorbitanmonolaurate condensed with 20 moles of ethylene oxide. The treatingagent was applied by means of a rotating roll in an amount such that0.66 percent solids were deposited on the filaments, based on the Weightof the filaments. The filament yarns were then divided into three parts.The first part was immediately hot drawn on a conventional draw-twistmachine at a draw ratio of 4.4lX with excellent results. The second partwas lagged for 7 days after which it was hot drawn on a conventionaldraw-twist machine at a draw ratio of 4.4lX with excellent results. Thethird part was lagged for 31 days after which it was hot drawn on aconventional draw-twist machine at a draw ratio of 4.4lX with goodresults.

As various changes in modification of this invention can be made withoutsacrificing any of its advantages and without departing from the spiritand scope thereof, it

Is to be understood, that all matter herein is to be interpretedstrictly as illustrative; as the only limitations of the invention arethose which appear in the following appended claims.

What is claimed is:

1. A method of preparing polyester filaments which comprises extrudingsaid filaments, immediately thereafter treating said filaments with anaqueous emulsion, the solids content of which consists essentially of(1) from about 20 to percent by weight of a member selected from thegroup consisting of a non-ionic surface active partial ester of apolyhydric alcohol having from about 2 to 8 carbon atoms and analiphatic carboxylic acid and a non-ionic surface active partial esterof a polyhydric alcohol having from about 2 to 8 carbon atoms and analiphatic carboxylic acid condensed with about 4 to 20 moles of ethyleneoxide and (2) from about 0 to 80 percent by weight of a non-ionicsurface active polyether prepared by condensing from about to 250 molesof ethylene oxide with a member selected from the group consisting ofwater-insoluble hydroxy fatty acids, esters of said acids and mixturesof said acids and esters, lagging said treated filaments for periods ofabout 12 hours to about 30 days and thereafter uniformly drawing saidfilaments.

2. A method of preparing polyester filaments which comprises extrudingsaid filaments, immediately thereafter treating said filaments with anaqueous emulsion, the solids content of which consists essentially offrom about 2 to 15 percent by weight of solids being selected from thegroup consisting of (1) about 60 percent by weight of sorbitanmonopalrnitate and about 40 percent by weight of castor oil condensedwith about 200 moles of ethylene oxide and (2) sorbitan monolauratecondensed with about 20 moles of ethylene oxide, lagging said treatedfilaments for periods of about 12 hours to about 30 days and thereafteruniformly drawing said filaments.

3. A method as defined in claim 2 wherein the polyester is polyethyleneterephthalate modified with about 6 percent, based on the weight of thepolyethylene terephthalate, of methoxy polyethylene glycol having amolecuuar weight of about 2000 and 0.125 percent, based on the weight ofthe polyethylene terephthalate of pentaerythritol.

4. A method as defined in claim 3 wherein the solids content of theaqueous emulsions consists of about 60 percent by weight of sorbitanmonopalmitate and about 40 percent by weight of castor oil condensedwith about 200 moles of ethylene oxide.

5. A method as defined in claim 3 wherein the solids content of theaqueous emulsion consists of sorbitan monolaurate condensed with 20moles of ethylene oxide.

References Cited UNITED STATES PATENTS ALEXANDER H. BRODMERKEL,

Primary Examiner.

F. S. WHISENHUNT, D. I. ARNOLD,

Assistant Examiners.

1. A METHOD OF PREPARING POLYESTER FILAMENTS WHICH COMPRISES EXTRUDINGSAID FILAMENTS, IMMEDIATELY THEREAFTER TREATING SAID FILAMENTS WITH ANAQUEOUS EMULSION THE SOLIDS CONTENT OF WHICH CONSISTS ESSENTIALLY OF (1)FROM ABOUT 20 TO 100 PERCENT BY WIEGHT OF A MEMBER SELECTED FROM THEGROUP CONSISTING OF A NON-IONIC SURFACE ACTIVE PARTICAL ESTER OF APOLYHYDRIC ALCOHOL HAVING FROM ABOUT 2 TO 8 CARBON ATOMS AND ANALIPHATIC CARBOXYLIC ACID AND A NON-IONIC SURFACE ACTIVE PARTIAL ESTEROF APOLYHYDRIC ALCOHOL HAVING FROM ABOUT 2 TO 8 CARBON ATOMS AND ANALIPHATIC CARBOXYLIC ACID CONDENSED WITH ABOUT 4 TO 20 MOLES OF ETHYLENEOXIDE AND (2) FROM ABOUT 0 TO 80 PERCENT BY WEIGHT OF A NON-IONICSURFACE ACTIVE POLYETHER PREPARED BY CONDENSING FROM ABOUT 150 TO 250MOLES OF ETHYLENE OXIDE WITH A MEMBER SELECTED FROM THE GROUP CONSISTINGOF WATER-INSOLUBLE HYDROXY FATTY ACID ESTERS OF SAID ACIDS AND MIXTURESOF SAID ACIDS AND ESTERS, LAGGING SAID TREATED FILAMENTS FOR PERIODS OFABOUT 12 HOURS TO ABOUT 30 DAYS AND THEREAFTER UNIFORMLY DRAWING SAIDFILAMENTS.